Barley Yellow Dwarf Virus

There was a high incidence of Barley Yellow Dwarf Virus (BYDV) across southern NSW in 2014. The level of infection was a result of ideal conditions for aphids during the autumn and early winter of 2014, following early sowing of cereal crops due to good rainfall in autumn.

Wedgetail wheat plus oat crops were the most commonly affected. However high levels of the virus were also found on early sown Wylah and Gregory crops. BYDV is not specific to variety and is likely to occur when infected aphids feed on early sown cereals.

Given the abundance of aphids in 2014 and the widespread nature of BYDV, it is likely that a high level of virus could be carried over to 2015, on host plants such as volunteer cereals or other grasses. Should significant aphid numbers be seen early in 2015, there is a high chance that BYDV could be a problem again for early sown crops.

Incidence of BYDV can be reduced by controlling aphids early in the growing season. To do this effectively, the application of an insecticide seed treatment is the most environmentally friendly and cost effective option. Seed treatments such as Emerge or Gaucho containing Imidacloprid, will provide aphid control for up to ten weeks without harming beneficial species. In an average season, this should significantly reduce the chances of BYDV infection. Where aphid pressure is particularly high, there may be further requirement for broad spectrum insecticidal control of aphids, once the seed treatment’s protection period has lapsed.

Based on the information available, it would be prudent to apply a seed treatment which controls aphids to all early sown cereal crops during 2015. Refer to article  on seed treatments for early insect control that provides further information.